Treatment of advanced squamous cell carcinoma of the external auditory canal: Critical analysis of persistent failures in diagnosis and surgery with a competing‐risk model

Abstract

Background: A series of temporal bone squamous cell carcinomas (TBSCCs) was analyzed with the aim of (i) better understanding the causes for the persistent high failure rate in advanced SCCs and (ii) discussing a possible way out from this stalemate in treatment.Methods: Forty-five TBSCCs consecutively treated surgically were reviewed. Results:The 5-year cumulative incidence for postoperative local recurrence was 41.8%. At multivariable analysis, pT3-4 stages were associated with eightfold relative incidence of developing local recurrence during follow-up (sHR = 9.06, 95% confidence interval [CI] = 1.18-69.46, p = 0.034) and cause-specific death (sHR = 7.95, 95%CI = 1.01-62.27, p = 0.048). Conclusions: The poor outcome in advanced TBSCC occurred because of local recurrence due to defective resection. The fundamental pitfall of surgery on advanced TBSCC appeared to be the insufficient knowledge of microscopic tumor growth in the different sites and subsites of the temporal bone. The serial histopathological study of the en bloc surgical specimen and autopsy temporal bones seems to represent a way to enhance our understanding of these tumors.

Clinical outcomes of temporal bone squamous cell carcinoma: A single‐institution experience

“… 10 Similarly, another well‐known staging system, the MPB staging system (derived from EACSCC), has also been investigated as a significant prognostic factor for patients with TBSCC by numerous studies. 6 , 8 , 9 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 Nevertheless, most of these studies only confirmed the MPB‐T classification as a significant prognostic factor rather than the overall stage, which is consistent with our results. Meanwhile, the majority of the above‐mentioned studies included a heterogeneous population of patients with TBSCC, which mainly consisted of patients with EACSCC; thus, the validity of the MPB‐T classifications for MESCC remains unclear.…”

“…Thus, generalization of these results to the entire TBC population may yield inadequate accuracy and reliability 10 . Similarly, another well‐known staging system, the MPB staging system (derived from EACSCC), has also been investigated as a significant prognostic factor for patients with TBSCC by numerous studies 6,8,9,11–18 . Nevertheless, most of these studies only confirmed the MPB‐T classification as a significant prognostic factor rather than the overall stage, which is consistent with our results.…”

“…However, its prognostic accuracy for TBSCC of other origins requires further investigation. Additionally, most TBSCC‐related studies have been reported in the form of case series, which mostly included small but highly heterogeneous populations, thereby greatly limiting the comprehensive understanding of potential prognostic factors 8,9 …”

“…Additionally, most TBSCC related studies have been re ported in the form of case series, which mostly included small but highly heterogeneous populations, thereby greatly limiting the comprehensive understanding of po tential prognostic factors. 8,9 Overall, successful treatment of TBSCC is complicated by several issues originating from its rarity. Integration of multi institutional clinical outcomes of TBSCC is urgently required and could contribute to a more comprehensive understanding of this rare disease.…”

Survival Outcomes in Squamous Cell Carcinoma of the External Auditory Canal: A Systematic Review and Meta-Analysis

“…Squamous cell carcinoma (SSC) is the most common malignant histotype in the temporal bone. Advanced SCC of the temporal bone (TBSCC) originating from the external auditory canal (EAC) is characterized by a dismal prognosis, mainly due to the local invasive behavior, the undetected ways of microscopic spreading, and the complexity of the anatomy of this region [ 3 , 4 ], which often leads to inadequate resections. Commonly reported negative prognostic factors include advanced tumor stage at presentation, nodal involvement, facial paralysis at diagnosis, non-anterior spread of the tumor (i.e., dura, petrous bone vs. anterior soft tissues invasion), and positive margins [ 3 ].…”